This disclosure is generally directed to imaging members, and more specifically, the present disclosure is directed to multi-layered photoconductive imaging members with a photogenerating layer, a charge transport layer, an optional hole blocking, or undercoat layer (UCL), and wherein the charge transport layer can be comprised of charge, especially hole transport components, and at least one polyol ester, which ester can function, for example, as a lubricant. A number of advantages are associated with the members illustrated herein, such as enabling extended life times and excellent wear resistant characteristics; very acceptable compatibility properties with toners generated by emulsion aggregation processes as illustrated in a number of Xerox patents; excellent PIDC cyclic stability at a number of different humidities, for example from about 25 to about 90 percent relative humidity; and improved toner cleanability.
In embodiments, the imaging members of the present disclosure possess a charge transport or top layer with excellent resistance to cracking against exposure to chemical vapors emitted from solvents. The charge transport layer's solvent vapor resistance and/or its anti-organic solvent characteristics can be determined by the known solvent vapor induced crystallization test, wherein the imaging member is subjected to exposure by the vapor of common organic solvents, such as for example, methylene chloride, isopropyl alcohol, propylene glycol, a cyclic siloxane of an eight member ring polydimethylsiloxane, tetrahydrofuran, toluene, and the like. As illustrated herein, in embodiments the imaging members of the present disclosure exhibit excellent cyclic/environmental stability; excellent wearability characteristics; enhanced toner image transfer efficiency to the image receiving member; extended lifetimes of, for example, up to 3,500,000 imaging cycles; acceptable and in some instances improved electrical characteristics; members which can be economically prepared with tunable or preselected properties depending, for example, on the amount of polyol ester lubricant contained in the charge transport layer; and improved compatibility with a number of toner compositions.
In embodiments, the photogenerating layer can be situated between the charge transport layer and the supporting substrate, and the hole blocking layer in contact with the supporting substrate can be situated between the supporting substrate and the photogenerating layer, which is comprised, for example, of the photogenerating pigments of U.S. Pat. No. 5,482,811, the disclosure of which is totally incorporated herein by reference, especially Type V hydroxygallium phthalocyanine, and generally metal free phthalocyanines, metal phthalocyanines, hydroxy gallium phthalocyanines, perylenes, titanyl phthalocyanines, vanadyl phthalocyanines, selenium, selenium alloys, azo pigments, and the like.
Processes of imaging, especially xerographic imaging and printing including digital, are also encompassed by the present disclosure. More specifically, the photoconductive imaging members of the present disclosure can be selected for a number of different known imaging and printing processes including, for example, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein charged latent images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 475 to about 950 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this disclosure are useful in color xerographic applications, particularly high-speed color copying and printing processes.